From the beginning of prototype (actual commercial) and model railroading, an operator has moved his locomotive around a fixed layout of track, choosing various alternative routes through the use of a turn-out, see FIG. 1. A detail drawing of a turn-out is show in FIG. 2. This turn-out consists of a lead-in leg, 203, a straight tangent leg, 201, and a curved divergent leg, 202. The three legs will be referred to hereafter as lead in, straight and curve. There are two track rails held at a fixed distance apart called the switch points, 204; on model railroads this is sometimes called a "swivel" piece. The switch points are moved from side to side by the throwbar, 205, which moves the curved closure rail, 208, against the top rail, 206, (straight position) or the straight closure rail, 209 against the bottom rail, 207. When the switch points are in its "straight" position, a locomotive entering the lead-in portion of the switch, 203, is directed to proceed in a straight path through the straight leg, 201, of the turn-out. When the switch points, 204, are in the "curved" position, a locomotive entering the lead-in portion of the switch is directed to proceed in a curved path through the curved leg, 202, of the turn-out.
The frog, 210, is flat metal area that supports the train wheels on the wheel rims as it runs through the area where the curved and straight closure rails end at the toe of frog, 211. In order to prevent the train wheels from slipping laterally through the frog area, guard rails, 212 or 213, are added to restrain the opposite wheel and keep the train on track. Turn-outs are produced as "right" or "left" hand types; the turn-out shown in FIG. 2 is a right handed turn-out.
A prototype turnout moves the switch points by actually bending the rails slightly as the throwbar, 205, is moved back and forth. The closure rails, 208 and 209, are attached at the frog toe position, 211. In model railroads, the switch points, 204, are often part of a fixed metal swivel that is pivoted near the toe of the frog, 211. This eliminates the added force to flex the closure rails as the throwbar is moved back and forth.
For either model railroads or prototype railroads, early designs of turnouts required that the switch points be moved by hand. Today, in most modem prototype rail yards and on many model railroads, the switch points, 204, are operated by remote control using pneumatic or electric motors or solenoids. On model railroads, these are called automatic or remote control turnouts. Typically, on model railroads, all of the remote control turn-out controls are routed back to a common layout control center, 120 in FIG. 1 which also has the power control transformer 112 for the powered track and layout accessories. Early model railroad turn-out designs would cause a derailment if the train entered through the curved or straight leg of a turnout that was switched in the opposite direction. For three-rail AC layouts, a "non-derailing" turn-out was introduced around 1950 which automatically detects a train entering the curved or the straight leg of a turn-out and toggles the switch points to the direction required; this allows a train to enter a turn-out from either the straight or curved leg without the operator having to specifically set the switch points. These non-derailing detectors can provide useful information for our invention on how a turn-out is occupied.
With remote control turn-outs, an operator can sit at his layout control center, 120 in FIG. 7, and by selecting which way each turn-out is set (straight or curve), he can direct his train anywhere around the layout he wishes. Thus, a turn-out is selected by operating the appropriate control lever, 701 through 704, which is connected to that specific turn-out. Operation of the selected turn-out occurs by moving the lever to either the "straight" position (often confirmed by lighting a green light) or to the "curve" position (often confirmed by lighting a red light). The movement of this control lever then operates the solenoid or motor, moving the throwbar, 205, to the desired position.
With the advent of various radio-controlled and tethered electronic locomotive throttles and layout controllers, the operator is no longer constrained to operate his turn-outs from the layout control center, 120. Because a hand-held controller has limited room for buttons and levers, other methods are used to select a turn-out or other accessory. One technique assigns identifying numbers to each remote control turn-out; the operator selects the desired turn-out by entering the identifying number (usually on a simple keypad) and pressing an additional button to activate the specific turn-out. Thus, while the operator has mobility and a single common controller, there is no substantial change in the method used to select and operate the turn-outs.
There are two methods for using identifying numbers for each turn-out. The first utilizes identifying numbers for each turn-out lever controller at a layout control center, 120, where each lever is connected to each specific turn-out. The second method uses electronics in each turn-out to hold the identifying numbers in local memory or using a group of toggle switches or program jumpers that are set by the user in each turn-out. The second method of using identifying numbers in the turn-out allows turn-outs to be selected and operated from direct transmission or from signals introduced onto the model railroad track or a common bus that connects to all turn-outs. The second method also eliminates much of the wiring between the turn-outs and a layout control center. Still, there is no substantial change in the method used to select and operate the remote control turn-outs; each turn-out must be selected by locating its specific control lever or finding and entering its unique identifying number. For most layouts this is a tedious task; the operator is diverted from watching his model trains and instead has to deal with turn-out identification. Since the operator is also involved in operating the train throttle plus a number of other tasks, this method of changing the turn-out position takes away from the joy of model railroading.